Injection moldings, injection-molding apparatus and method thereof

ABSTRACT

Disclosed are injection moldings, an injection-molding apparatus and a method thereof. The injection-molding apparatus comprises: a cavity mold having a cavity; a core mold having a core surface to form a molding space for injection moldings when being joined to the cavity mold; a heating unit for heating the cavity mold or the core mold; a cooling unit for cooling the cavity mold or the core mold; and a patterning stamp having a micrometer or nanometer sized pattern and provided on an inner surface of the molding space. According to the injection-molding apparatus, a micrometer or nanometer sized pattern is formed on a surface of injection moldings so as to have a super-hydrophobic characteristic and an optical characteristic, and a micrometer or nanometer sized pattern of a complex structure can be implemented.

TECHNICAL FIELD

The present invention relates to injection moldings, and moreparticularly, to injection moldings, an injection-molding apparatus anda method thereof, in which a pattern of a micrometer or nanometer sizecan be simply formed on a surface of injection moldings so as to have asuper-hydrophobic characteristic and an optical characteristic, and amicrometer or nanometer sized pattern of a complex structure can beimplemented.

BACKGROUND ART

Generally, a refrigerating cycle device is provided at a refrigerator,an conditioner, etc. The refrigerating cycle device includes a condenserand an evaporator. The condenser performs heat exchange with peripheralair by emitting heat outwardly, and the evaporator performs heatexchange with peripheral air by absorbing external heat. The condenserand the evaporator are called as a heat exchanger.

As the heat exchanger for an evaporator absorbs external heat, moistureis condensed on a surface of the heat exchanger for an evaporatorthereby to form droplets. As the droplets are frozen, frost isgenerated. The frost lowers an efficiency of the heat exchanger, therebybeing periodically removed by a defrosting device.

In order to enhance an efficiency of the heat exchanger, the heatexchanger is processed so as to have a super-hydrophobic characteristicthereon. Since the surface of the heat exchanger having asuper-hydrophobic characteristic has a structure of a micrometer ornanometer size, a surface friction due to a fluid is decreased andthereby droplets are effectively removed.

A method for processing a surface of a heat exchanger includes a plasmaenhanced chemical vapor deposition (PECVD), a plasma polymerization,polypropylene, a nano-structured carbon film, etc.

The above methods serve to change a shape of a surface of the heatexchanger through complicated chemical processes, or serve to implementa surface of the heat exchanger having a hydrophobic characteristic bychanging a surface energy of a material. The above methods requireexpensive processes or long processing time, thereby having a difficultyin being utilized for a massive production.

Injection moldings formed of a plastic material or a product formed of aplastic material is provided with a micrometer or nanometer sizedpattern thereon so as to have a super-hydrophobic characteristic or anoptical characteristic. In order to form a micrometer or nanometer sizedpattern on a surface of a product or injection moldings formed of aplastic material, the plastic moldings have to undergo aninjection-molding process. Then, the plastic moldings undergo apost-processing such as a printing process, a stamping process or asurface machining process.

However, the post-processing requires a high cost. A hot-stampingprocess is widely used to form a micrometer or nanometer sized pattern.However, the hot-stamping process can be applied to form a simplepattern, but can not be applied to form a complicated pattern having ahydrophobic characteristic, etc.

DISCLOSURE OF THE INVENTION

Therefore, it is an object of the present invention to provide injectionmoldings, an injection-molding apparatus and a method thereof, in whicha pattern of a micrometer or nanometer size can be simply formed on asurface of injection moldings so as to have a super-hydrophobiccharacteristic and an optical characteristic, and a micrometer ornanometer sized pattern of a complex structure can be implemented.

To achieve these objects, there is provided an injection-moldingapparatus, comprising: a cavity mold having a cavity; a core mold havinga core surface to form a molding space for injection moldings when beingjoined to the cavity mold; a heating unit for heating the cavity mold orthe core mold; a cooling unit for cooling the cavity mold or the coremold; and a patterning stamp having a micrometer or nanometer sizedpattern and provided on an inner surface of the molding space.

The patterning stamp may be provided both on an inner surface of thecavity of the cavity mold and on the core surface of the core mold.

The patterning stamp is mounted at the cavity mold or the core mold by astamp fixing unit.

The patterning stamp may be fixed to the cavity mold or the core mold bya vacuum.

According to another aspect of the present invention, there is providedan injection-molding apparatus comprising: a cavity mold having acavity; a core mold having a core surface to form a molding space forinjection moldings when being joined to the cavity mold; a heating unitfor heating the cavity mold or the core mold; a cooling unit for coolingthe cavity mold or the core mold; and a micrometer or nanometer sizedpattern provided on an inner surface of the molding space.

The pattern is provided on an inner surface of the cavity of the cavitymold and on the core surface of the core mold.

Injection moldings fabricated at injection moldings space formed by thecavity of the cavity mold and the core surface of the core mold have anoptical characteristic of a hologram on a partial surface or an entiresurface thereof.

Injection moldings fabricated at injection moldings space formed by thecavity of the cavity mold and the core surface of the core mold have asuper-hydrophobic characteristic on a partial surface or an entiresurface thereof.

To achieve these objects, there is also provided an injection-moldingmethod, comprising: heating a cavity mold into a preset temperature;engaging the cavity mold with a core mold when the cavity mold is heatedto the preset temperature; injecting a melted molding material into amolding space formed by the cavity of the cavity mold and the coresurface of the core mold; cooling the cavity mold and the core mold; andseparating the cavity mold and the core mold from each other, therebyobtaining injection moldings.

To achieve these objects, there is still also provided injectionmoldings fabricated by an injection-molding apparatus having apatterning stamp on which a pattern is formed in a molding space, inwhich the injection moldings has a micrometer or nanometer sized patternon a surface thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front sectional view showing an injection-molding apparatusaccording to a first embodiment of the present invention;

FIG. 2 is a sectional view showing a stamp fixing unit of theinjection-molding apparatus of FIG. 1;

FIG. 3 is a front view showing an injection-molding machine having theinjection-molding apparatus of FIG. 1;

FIG. 4 is a front sectional view showing an injection-molding apparatusaccording to a second embodiment of the present invention;

FIG. 5 is a flowchart showing an injection-molding method according tothe present invention; and

FIGS. 6 and 7 are front sectional views showing an operation state ofthe injection-molding apparatus according to a first embodiment of thepresent invention, respectively.

MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

Hereinafter, an injection-molding apparatus and a method thereofaccording to the present invention will be explained in more detail withreference to the attached drawings.

FIG. 1 is a front sectional view showing an injection-molding apparatusaccording to a first embodiment of the present invention.

As shown, the injection-molding apparatus comprises a cavity mold 100having a cavity C1; a core mold 200 having a core surface C2 to form amolding space C for injection moldings when being joined to the cavitymold 100.

The cavity mold 100 includes a base member 110; a body member 120 havingthe cavity C1 at one side thereof, having a receiving space 121 at anopposite side to the cavity C1, and fixedly-coupled to the base member110; and an injecting pipe 130 coupled to the body member 120 so as tobe communicated with the cavity C1, for injecting a melted moldingmaterial.

The base member 110 is formed to have a certain area.

The body member 120 includes a body portion 122 having a certain shape;the cavity C1 formed on one surface of the body portion 122 so as tohave one opened side; a coupling recess 123 formed on one surface of thebody portion 122 so as to be disposed at a periphery of the cavity C1;and the receiving space 121 formed at the body portion 122 so as to bedisposed at an opposite side to the cavity C1. The receiving space 121is formed at the body portion 122 of the body member 120 so as to have acertain size and depth, and one side of the receiving space 121 isopened. A partition wall is formed between the receiving space 121 andthe cavity C1.

The core mold 200 includes a base member 210, a plurality of connectionmembers 220 having a certain length and coupled to the base member 210,and a core body 230 having a core surface C2 and coupled to theplurality of connection members 220.

The core body 230 includes a body portion 231 having a certain shape,the core surface C2 that forms the molding space C together with thecavity C1, and a coupling protrusion 232 protruding from a periphery ofthe core surface C2 and inserted into the coupling recess 123 of thecavity mold 100.

The molding space C formed by the cavity C1 of the cavity mold 100 andthe core surface C2 of the core mold 200 may have variously formsaccording to a shape of injection moldings to be injected.

A heating unit 300 for heating the cavity mold 100 is provided at thecavity mold 100.

The heating unit 300 includes an electro-thermal wire disposed at thebody member 120 of the cavity mold 100 so as to be disposed at aperiphery of the cavity C1, and a wire for supplying electricity to theelectro-thermal wire.

The heating unit 300 may be provided at the core mold 200.

A cooling unit 400 for selectively cooling the cavity mold 100 isprovided at the cavity mold 100.

The cooling unit 400 includes a cooling plate 410 movably disposed atthe receiving space 121 of the body member 120 of the cavity mold 100,and a driving unit 420 for reciprocating the cooling plate 410 therebycontacting/separating the cooling plate 410 onto/from an inner surfaceof the cavity C1.

The cooling plate 410 includes a plate 411 having a certain area, and apassage disposed in the plate 411 and through which a cooling mediumflows. Preferably, the cooling plate 410 is formed of a copper material.

Preferably, the driving unit 420 includes a hydraulic cylinder connectedto the cooling plate 410 for linearly reciprocating the cooling plate410.

The driving unit 420 may be implemented as various devices.

When the cavity mold 100 is cooled by the cooling unit 400, the coolingplate 410 is moved by the driving unit 420 thus to contact an innersurface of the receiving space 121. Here, the inner surface of thereceiving space 121 is the closest to the cavity C1. As the coolingplate 410 contacts an inner surface of the receiving space 121, cool airgenerated from the cooling plate 410 cools the cavity C1 via the bodyportion 122 of the body member 120 of the cavity mold 100. However, whenthe cooling operation for the cavity mold 100 is stopped, the coolingplate 410 is moved by the driving unit 420 thereby to be separated fromthe inner surface of the receiving space 121.

The cooling unit 400 may be provided at the core mold 200.

A patterning stamp 500 having a micrometer or nanometer sized pattern isprovided on an inner surface of the cavity C1 of the cavity mold 100.

The patterning stamp 500 is fixed to the cavity mold 100 by a stampfixing unit 600.

The stamp fixing unit 600 can fix the patterning stamp 500 by using avacuum. The stamp fixing unit 600 includes a suction passage 610 formedat the cavity mold 100 so as to be communicated with the cavity C1 ofthe cavity mold 100, and a vacuum generating unit 620 for sucking thepatterning stamp 500 disposed in the cavity C1 to an inner surface ofthe cavity C1 by applying a vacuum to the suction passage 610.

When the patterning stamp 500 is positioned on the inner surface of thecavity C1 of the cavity mold 100 and then a vacuum is applied to thesuction passage by the vacuum generating unit 620, the patterning stamp500 is fixed to the inner surface of the cavity C1 by the vacuum. Aclamp for support-fixing the patterning stamp 500 may be furtherprovided.

As another embodiment, the stamp fixing unit 600 is implemented as theclamp. As shown in FIG. 2, the stamp fixing unit 600 includes asupporting member 630 for supporting the patterning stamp 500; and acoupling member 640 coupled to the supporting member 630 and the cavitymold 100, for fixing/releasing the patterning stamp 500 bypressurizing/releasing the supporting member 630.

A receiving recess 233 for receiving the stamp fixing unit 600 whenbeing joined to the cavity mold 100 is provided at one side of the coremold 200.

The patterning stamp 500 has a certain pattern 520 on one surface of thestamp 510 having a certain area. The pattern 520 may be formed on apartial or entire surface of the stamp 510. The pattern 520 formed atthe stamp 510 has a micrometer or nanometer sized structure.

A method for forming the pattern 520 on the stamp 510 includes aBiomimetics method. The Biomimetics method includes a sputteringprocess, an adhesive bonding process, a gold coating process, a nickelelectro-forming process, a stripping process, etc., which is disclosedin the Patent No. 10-2005-0063692.

A desire complicated pattern can be formed on the stamp by using theBiomimetics method.

A method for processing the patterning stamp 500 includes a mechanicalprocess, a laser process, an LICA process, a semiconductor fabricatingprocess, a MEMS process, etc.

As the method for forming the pattern 520 on the stamp 510, variousmethods rather than the above methods may be used.

Preferably, the patterning stamp 500 is formed of a nickel material.

The patterning stamp 500 may be formed of a planar plate or a curvedplate.

As shown in FIG. 3, the cavity mold 100 having the heating unit 600, thecooling unit 400, and the patterning stamp 500 is preferably fixed to afixing unit 10 of an injection molding machine (M). Preferably, the coremold 200 is mounted at a mover 20 of the injection molding machine (M).As the mover 20 is operated, the core mold 200 is moved, and thereby thecavity mold 100 and the core mold 200 are joined to each other orseparated from each other.

The patterning stamp 500 may not be mounted on the inner surface of thecavity C1 of the cavity mold 100, but may be mounted on the core surfaceC2 of the core mold 200.

The patterning stamp 500 may be provided on the core surface C2 of thecore mold 200 by the stamp fixing unit. The stamp fixing unit may havethe aforementioned configuration.

The patterning stamp 500 may be provided on the inner surface of thecavity C1 of the cavity mold 100, and the core surface C2 of the coremold 200, respectively. In this case, the pattering stamp 500 is fixedto the inner surface of the cavity C1 of the cavity mold 100 and thecore surface C2 of the core mold 200 by the stamp fixing unit.

FIG. 4 is a front sectional view showing an injection-molding apparatusaccording to a second embodiment of the present invention.

As shown, the injection-molding apparatus comprises a cavity mold 100having a cavity C1; a core mold 200 having a core surface to form amolding space C together with the cavity C1 when being joined to thecavity mold 100; a heating unit 300 for heating the cavity mold 100 orthe core mold 200; a cooling unit 400 for cooling the cavity mold 100 orthe core mold 200; and a pattern 520′ having a micrometer or nanometersized structure directly formed on an inner surface of the molding spaceC.

The cavity mold 100, the core mold 200, the heating unit 300, and thecooling unit 400 have the same configuration as those of the firstembodiment.

The pattern 520′ may be formed on an entire or partial inner surface ofthe cavity C1 of the cavity mold 100.

The pattern 520′ formed on the inner surface of the cavity C1 of thecavity mold 100 has a micrometer or nanometer sized structure.

A method for forming the pattern 520′ on the inner surface of the cavityC1 of the cavity mold 100 may include a mechanical process, a laserprocess, an LIGA process, a semiconductor fabricating process, a MEMSprocess, etc.

According to the mechanical process, a pattern having a sizecorresponding to approximately 1 micrometer can be implemented.According to the laser process, a pattern having a size corresponding toseveral micrometers can be implemented. According to the semiconductorfabricating process, the cavity mold 100 undergoes a coating process, anetching process, etc., thereby forming a pattern on the inner surface ofthe cavity C1 of the cavity mold 100.

The pattern 520′ may be formed on the core surface C2 of the core mold200, not on the inner surface of the cavity C1 of the cavity mold 100.

The pattern 520′ may be respectively formed on the core surface C2 ofthe core mold 200 and on the inner surface of the cavity C1 of thecavity mold 100.

The injection-molding apparatus was explained based on the first andsecond embodiments of the present invention. However, various techniquesmay be implemented.

FIG. 5 is a flowchart showing an injection-molding method according tothe present invention.

As shown, the injection-molding method comprises: heating the cavitymold 100 into a preset temperature; and engaging the cavity mold 100with the core mold 200 when the cavity mold 100 is heated to the presettemperature.

Preferably, the cavity mold 100 is heated at a temperature of 120° C.which is less than a melting temperature for injection moldings.

Once the temperature of the cavity mold 100 is risen, a melted moldingmaterial such as resin has an enhanced flow/transfer characteristic, andhas a low viscosity. Accordingly, the melted molding material issmoothly sucked into the pattern of the patterning stamp 500, therebybeing directly patterned on a surface of the injection moldings.

Then, a step for injecting the melted molding material into a moldingspace formed by the cavity C1 of the cavity mold 100 and the coresurface C2 of the core mold 200 is performed. Then, a step for coolingthe cavity mold 100 and the core mold 200 after the melted moldingmaterial is injected into the molding space is performed.

Then the cavity mold 100 and the core mold 200 are separated from eachother, thereby obtaining injection moldings disposed at the moldingspace C.

The temperature of the melted molding material can be risen by heatingonly the cavity mold 100 or only the core mold 200.

Hereinafter, an operation of the injection-molding apparatus will beexplained.

According to the injection-molding apparatus according to the firstembodiment, when power is supplied to the wire of the heating unit 300under a state that the cavity mold 100 mounted at the fixing unit 10 ofthe injection molding machine (M) is spaced from the core mold 200mounted at the mover 20 of the injection molding machine (M) with acertain distance, heat is generated from the electro-thermal wirethereby to heat the cavity mold 100.

Since the heating unit 300 is disposed at a periphery of the cavity C1,the cavity C1 is heated more rapidly than other parts. Herein, thecavity mold 100 does not come in contact with the cooling unit 400.

When the cavity C1 of the cavity mold 100 is heated into a presettemperature, the cavity mold 100 and the core mold 200 are joined toeach other as the core mold 200 is moved by the mover 20 of theinjection molding machine (M) as shown in FIG. 6. When the cavity mold100 is heated into the preset temperature, the power supplied to theheating unit 400 is stopped.

When a melted molding material is injected into the injecting pipe 130of the cavity mold 100, the melted molding material is introduced intothe molding space C through the injecting pipe 130 thereby to fill themolding space C. Since the mold and the molding space have a high innertemperature, the melted molding material has an enhanced flow/transfercharacteristic and a low viscosity. As a result, the melted moldingmaterial is rapidly filled in the molding space, and is sufficientlyintroduced into the pattern 520 formed on the patterning stamp 500.

While the melted molding material is injected into the molding space C,the driving unit 420 is operated thereby to contact the cooling plate410 to the inner surface of the receiving space 121. As the coolingplate 410 contacts the inner surface of the receiving space 121, thecavity mold 100 is cooled thereby to harden the melted molding materialfilled in the molding space C.

As shown in FIG. 7, the cavity mold 100 and the core mold 200 areseparated from each other by moving the core mold 200, thereby obtainingthe injection moldings formed in the molding space C. While the cavitymold 100 and the core mold 200 are separated from each other, the cavitymold 100 is heated to a preset temperature.

The above process is repeated, thereby fabricating injection moldings.

When the pattern 520 of the patterning stamp 500 is damaged, the pattern520 is replaced by a new patterning stamp 500. When another pattern isto be formed on a surface of the injection moldings, the patterningstamp 500 is replaced by a new one. Since the patterning stamp 500 canbe replaced by a new one, various patterns can be formed on the surfaceof the injection moldings. Also, when the pattern 520 of the patterningstamp 500 is damaged, the patterning stamp 500 can be easily replaced bya new one.

The melted molding material has an enhanced flow/transfer characteristicand has a low viscosity by heating the cavity mold 100, thereby forminga micrometer or nanometer sized pattern on a surface of the injectionmoldings.

The pattern formed on the partial or entire surface of the injectionmoldings has a micrometer or nanometer size. The surface of theinjection moldings on which the pattern is formed has an opticalcharacteristic of rainbow colors of a hologram, a super-hydrophobiccharacteristic, a stainless hair line finishing characteristic, etc.

The injection moldings may be formed of synthetic resin-based materials,or may be formed of various materials such as aluminum.

An operation of the injection-molding apparatus according to the secondembodiment of the present invention will be explained.

The operation of the injection-molding apparatus according to the secondembodiment of the present invention is the same as the operation of theinjection-molding apparatus according to the first embodiment of thepresent invention. The pattern is formed on the surface of the injectionmoldings obtained in the molding space by a pattern formed on the innersurface of the cavity C1 of the cavity mold 100, or a pattern formed onthe core surface C2 of the core mold 200.

The pattern formed on the surface of the injection moldings has amicrometer or nanometer size. The surface of the injection moldings onwhich the pattern is formed has an optical characteristic of rainbowcolors of a hologram, a super-hydrophobic characteristic, a stainlesshair line finishing characteristic, etc. In order for the pattern formedon the surface of the injection moldings to have a hydrophobiccharacteristic, a contact angle between the pattern and water has to bemore than 90°. In order for the pattern formed on the surface of theinjection moldings to have a super-hydrophobic characteristic, a contactangle between the pattern and water has to be more than 150°.

When a pattern formed on the cavity mold 100 or the core mold 200 isdamaged, the cavity mold 100 or the core mold 200 is replaced by a newone.

In order for a pattern formed on a surface of the injection moldingsfabricated according to the first embodiment or the second embodiment tohave an optical characteristic of rainbow colors of a hologram, theinjection moldings are preferably formed of a polycarbonate-basedplastic material. When the injection moldings are formed of apolycarbonate-based plastic material, a hologram effect can bemaximized.

In order for the pattern formed on the surface of the injection moldingsto have a super-hydrophobic characteristic, an ABS-based resin ispreferably used.

In the present invention, a micrometer or nanometer sized pattern isformed on an inner surface of the molding space of the cavity mold 100or the core mold 200, and the patterning stamp 500 having the pattern isprovided on the inner surface of the molding space. Also, a meltedmolding material injected into the molding space of the cavity mold 100or the core mold 20 has an enhanced flow/transfer characteristic and hasa low viscosity.

Accordingly, a micrometer or nanometer sized pattern is formed on thesurface of the injection moldings formed at the molding space of thecavity mold 100 or the core mold 200. The surface of the injectionmoldings having the pattern thereon has an optical characteristic, asuper-hydrophobic characteristic, etc.

The pattern of the injection moldings can be applied to a product forprevention of a counterfeit.

The pattern has a size enough to form a hologram. The injection moldingshaving a hologram may be a product that constitutes an appearance of arefrigerator, or the injection moldings may be attached onto an outersurface of a refrigerator. When the pattern that represents a hologramis provided at a door or a body of a refrigerator, the refrigerator canhave an enhanced appearance.

The pattern has a size enough to implement a super-hydrophobiccharacteristic, and the injection moldings having a super-hydrophobiccharacteristic may be a product inside a refrigerator. When theinjection moldings having a super-hydrophobic characteristic is appliedto a heat exchanger for a condenser or a heat exchanger for anevaporator of a refrigerator, the heat exchanger for a condenser or theheat exchanger for an evaporator has an enhanced heat exchangeefficiency.

Furthermore, since the melted molding material has an enhancedflow/transfer characteristic and has a low viscosity, the melted moldingmaterial is rapidly filled in the molding space of the cavity mold orthe core mold. Also, since the filled molding material is directlycooled, a time for forming the injection moldings having a patternthereon is shortened.

The present invention has the following effects.

A micrometer or nanometer sized pattern is formed on an inner surface ofthe molding space of the cavity mold and the core mold, or thepatterning stamp having a micrometer or nanometer sized pattern isprovided on an inner surface of the molding space of the cavity mold andthe core mold. A melted molding material injected into the molding spaceof the cavity mold and the core mold has an enhanced flow/transfercharacteristic, and has a low viscosity.

Accordingly, a micrometer or nanometer sized pattern is formed on asurface of injection moldings formed at the molding space of the cavitymold and the core mold. The injection moldings have a super-hydrophobiccharacteristic and an optical characteristic thereon.

Furthermore, since the melted molding material injected into the moldingspace of the cavity mold and the core mold has an enhanced flow/transfercharacteristic and has a low viscosity, the melted molding material israpidly filled in the molding space of the cavity mold and the coremold. Also, since the filled molding material is directly cooled, a timefor forming the injection moldings having a pattern thereon is shortenedthereby to enhance a productivity.

Since the injection moldings have an optical characteristic or asuper-hydrophobic characteristic thereon, if the injection moldings areimplemented as fins of a heat exchanger, the heat exchanger has asuper-hydrophobic characteristic. Accordingly, water drops formed on theheat exchanger are directly discharged out, thereby maximizing a heattransferring efficiency of the heat exchanger.

When the injection moldings are implemented as a door for arefrigerator, a pattern having an optical characteristic of rainbowcolors of a hologram can be provided on a surface of the door for arefrigerator. Accordingly, the door for a refrigerator has an enhancedappearance, so that a user can have mysterious feeling and an enhancedsatisfaction degree.

When the injection moldings are implemented as an outer case for homeelectric appliances such as an air conditioner and a washing machine, apattern having an optical characteristic of rainbow colors of a hologramcan be provided on a partial surface or an entire surface of the outercase. As a result, the home electric appliances can have an enhancedappearance.

It will also be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover modifications and variationsof this invention provided they come within the scope of the appendedclaims and their equivalents.

1. An injection-molding apparatus, comprising: a cavity mold having acavity; a core mold having a core surface to form a molding space forinjection moldings when being joined to the cavity mold; a heating unitfor heating the cavity mold or the core mold; a cooling unit for coolingthe cavity mold or the core mold; and a patterning stamp having amicrometer or nanometer sized pattern and provided on an inner surfaceof the molding space.
 2. The injection-molding apparatus of claim 1,wherein the patterning stamp is provided on an inner surface of thecavity of the cavity mold, or on the core surface of the core mold. 3.The injection-molding apparatus of claim 1, wherein the patterning stampis fixed to the cavity mold or the core mold by a stamp fixing unit. 4.The injection-molding apparatus of claim 3, wherein the stamp fixingunit comprises: a supporting member for supporting the patterning stamp;and a coupling member coupled to the supporting member and the cavitymold, for fixing/releasing the patterning stamp bypressurizing/releasing the supporting member.
 5. The injection-moldingapparatus of claim 3, wherein the stamp fixing unit uses a vacuum. 6.The injection-molding apparatus of claim 3, wherein the stamp fixingunit comprises: a suction passage formed at the cavity mold or the coremold so as to be communicated with the cavity of the cavity mold or thecore surface of the core mold; and a vacuum generating unit for suckingthe patterning stamp to an inner surface of the cavity or the coresurface by applying a vacuum to the suction passage.
 7. Theinjection-molding apparatus of claim 1, wherein the patterning stamp isformed of a planar plate. 15
 8. The injection-molding apparatus of claim1, wherein the patterning stamp is formed of a curved plate.
 9. Aninjection-molding apparatus, comprising: a cavity mold having a cavity;a core mold having a core surface to form a molding space for injectionmoldings when being joined to the cavity mold; a heating unit forheating the molding space; a cooling unit for cooling the molding space;and a micrometer or nanometer sized pattern provided on an inner surfaceof the molding space.
 10. The injection-molding apparatus of claim 9,wherein the pattern is provided on a partial or entire inner surface ofthe cavity of the cavity mold.
 11. The injection-molding apparatus ofclaim 9, wherein the pattern is provided on a partial or entire coresurface of the core mold.
 12. The injection-molding apparatus of claim 1or 9, wherein the heating unit comprises: an electro-thermal wiredisposed at the cavity mold so as to be disposed at a periphery of thecavity; and a wire for supplying electricity to the electro-thermalwire.
 13. The injection-molding apparatus of claim 1 or 9, wherein thecooling unit comprises: a cooling plate movably disposed at a receivingspace of the cavity mold so as to be positioned at an opposite side tothe cavity; and a driving unit for reciprocating the cooling platethereby contacting/separating the cooling plate onto/from an innersurface of the cavity.
 14. The injection-molding apparatus of claim 13,wherein the driving unit comprises a hydraulic cylinder.
 15. Theinjection-molding apparatus of claim 1 or 9, wherein the cavity moldcomprises: a base member; a body member having the cavity at one sidethereof, having a receiving space for the cooling unit at an oppositeside to the cavity, and fixedly-coupled to the base member; and aninjecting pipe coupled to the body member so as to be communicated withthe cavity, for injecting a melted molding material.
 16. Theinjection-molding apparatus of claim 1 or 9, wherein the cavity mold isfixed to a fixing unit of an injection molding machine, and the coremold is mounted at a mover of the injection molding machine thereby tomove.
 17. The injection-molding apparatus of claim 1, wherein theinjection moldings fabricated at the molding space formed by the cavityof the cavity mold and the core surface of the core mold has an opticalcharacteristic of a hologram on a surface thereof.
 18. Theinjection-molding apparatus of claim 1, wherein the injection moldingsfabricated at the molding space formed by the cavity of the cavity moldand the core surface of the core mold has a super-hydrophobiccharacteristic on a surface thereof by a pattern of the patterningstamp.
 19. The injection-molding apparatus of claim 9, wherein theinjection moldings fabricated at the molding space formed by the cavityof the cavity mold and the core surface of the core mold has an opticalcharacteristic of a hologram by a pattern of the patterning stamp. 20.The injection-molding apparatus of claim 9, wherein the injectionmoldings fabricated at the molding space formed by the cavity of thecavity mold and the core surface of the core mold has asuper-hydrophobic characteristic by a pattern of the patterning stamp.21. An injection-molding apparatus, characterized in that a micrometeror nanometer sized pattern is formed on an inner wall of a molding spacein which a melted molding material is filled.
 22. An injection-moldingapparatus comprising a patterning stamp having a micrometer or nanometersized pattern on an inner wall of a molding space in which a meltedmolding material is filled.
 23. An injection-molding method, comprising:heating a cavity mold into a preset temperature; engaging the cavitymold with a core mold when the cavity mold is heated to the presettemperature; injecting a melted molding material into a molding spaceformed by the cavity of the cavity mold and the core surface of the coremold; immediately cooling the cavity mold and the core mold when themelted molding material is injected into the molding space; andseparating the cavity mold and the core mold from each other, therebyobtaining injection moldings.
 24. The injection-molding method of claim23, wherein the cavity mold is heated at a temperature of 120° C. whichis less than a melting temperature for injection moldings.
 25. Injectionmoldings fabricated by an injection-molding apparatus having apatterning stamp on which a pattern is formed in a molding space,characterized in that a micrometer or nanometer sized pattern is formedon a surface of the injection moldings.
 26. Injection moldingsfabricated by heating a mold having a patterning stamp on which apattern is formed into a high temperature and then by melting asynthetic resin, characterized in that a micrometer or nanometer sizedpattern is formed at one side on a surface of the injection moldings.27. The injection moldings of claim 25 or 26, wherein the pattern has asize enough to form a hologram.
 28. The injection moldings of claim 25or 26, wherein the pattern has a size enough to implement asuper-hydrophobic characteristic.
 29. The injection moldings of claim 25or 26, wherein the pattern is applied to a product for prevention of acounterfeit.
 30. The injection moldings of claim 25 or 26, wherein thepattern has a size enough to form a hologram, and the injection moldingshaving a hologram are provided on an outer surface of a refrigerator.31. The injection moldings of claim 25 or 26, wherein the pattern has asuper-hydrophobic characteristic when a contact angle with water is morethan 90°, and the injection moldings having a super-hydrophobiccharacteristic are provided in a refrigerator.
 32. The injectionmoldings of claim 25 or 26, wherein the pattern has a size enough toform a hologram, and the pattern is formed on a part of the injectionmoldings.